• 한국해양공학회지
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• 제19권2호
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• pp.12-18
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• 2005

Typhoon Maemi landed on the southeast coast of Korea and caused a severe storm surge in Jinhae Bay and Masan Bay. The tide gage in Masan Port recorded the storm surge of a maximum of more than 2m and the area of more than 700m from the Seo Hang Wharf was flooded by the storm surge. They had not met such an extremely severe storm surge since the opening of the port. Then storm surge was hindcasted with a numerical model. The typhoon pressure was approximated by Myers' empirical model and super gradient wind around the typhoon eye wall was considered in the wind estimation. The land topography surrounding Jinhae Bay and Masan Bay is so complex that the computed wind field was modified with the 3D-MASCON model. The motion of seawater due to the atmospheric forces was simulated using a one-layer model based on non-linear long wave approximation. The Janssen's wave age dependent drag coefficient on the sea surface was calculated in the wave prediction model WAM cycle 4 and the coefficient was inputted to the storm surge model. The result shows that the storm surge hindcasted by the numerical model was in good agreement with the observed one.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2021년도 학술발표회
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• pp.153-153
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• 2021

Storm Storm event is one of major issues in South Korea due to devastating damage at its landfall. A series of statistical study on the historical typhoon records consistently insist that the typhoon translation speed (TS) is on slowdown trend annually, and thus provides an urgent topic in assessing the extreme storm surge under future climate change. Even though TS has been regarded as a principal contributor in storm surge dynamics, only a few studies have considered its impact on the storm surge. The landfall angle (LA), another key physical factor of storm surge also needs to be further investigated along with TS. This study aims to elucidate the interaction mechanism among TS, LA, coastal geometry, and storm surge synthetically by performing a series of simulations on the idealized geometries using Delft3D FM. In the simulation, various typhoons are set up according to different combinations of TS and LA, while their trajectories are assumed to be straight with the constant wind speed and the central pressure. Then, typhoons are subjected to make landfall over a set of idealized geometries that have different depth profiles and layouts (i.e., open coasts or bays). The simulation results show that: (i) For the open coasts, the maximum surge height (MSH) increases with increasing TS. (ii) For the constant bed level, a typhoon normal to the coastline resulted in peak MSH due to the lowest effect of the coastal wave. (iii) For the continental shelf with different widths, the slow-moving typhoon will generate the peak MSH around a small LA as the shelf width becomes narrow. (iv) For the bay, MSH enlarges with the ratio of L/E (the length of main-bay axis /gate size) dropping, while the greatest MSH is at L/E=1. These findings suggest that a fast-moving typhoon perpendicular to the coastline over a broad continental shelf will likely generate the extreme storm surge hazard in the future, as well as the slow-moving typhoon will make an acute landfall over a narrow continental shelf.

• 한국해양공학회지
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• 제26권1호
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• pp.47-53
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• 2012

A coastal flood area was predicted using the empirical superposition of the typhoon surge level and typhoon wave height along the Busan coastal area. The historical typhoon damages were reviewed, and the coastal topography was measured using VRS-GPS. A FEMA formula was applied to estimate the coastal flood area in a typhoon case when the measured and predicted data of typhoon waves are not available. The results in the area of Haeundae beach and Gwangalli beach were verified using the flood area data from the case of Typhoon Maemi (2003). If a Hurricane Katrina class typhoon were to pass through the Maemi trajectory, the areathat would be flooded along theBusan coastal area was predicted and compared with the results of the Maemi case. Because of the lack of ocean environment data such as data for the sea level, waves, bathymetry, wind, pressure, etc., it is hard to improve the prediction accuracy for the coastal flood area in the typhoon case, which could be reflected in the policy to mitigate a typhoon's impact. This paper discusses the kinds of ocean environment information that is needed to predict a typhoon's impact with better accuracy.

• Ocean and Polar Research
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• 제31권4호
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• pp.369-377
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• 2009

Performance of the Korea Ocean Research and Development Institute (KORDI) operational storm surge prediction system for the Korean coast is presented here. Results for storm surge hindcasts and forecasts calculations were analyzed. The KORDI storm surge system consists of two important components. The first component is atmospheric models, based on US Army Corps of Engineers (CE) wind model and the Weather Research and Forecasting (WRF) model, and the second components is the KORDI-storm surge model (KORDI-S). The atmospheric inputs are calculated by the CE wind model for typhoon period and by the WRF model for non-typhoon period. The KORDI-S calculates the storm surges using the atmospheric inputs and has 3-step nesting grids with the smallest horizontal resolution of ${\sim}$300 m. The system runs twice daily for a 72-hour storm surge prediction. It successfully reproduced storm surge signals around the Korean Peninsula for a selection of four major typhoons, which recorded the maximum storm surge heights ranging from 104 to 212 cm. The operational capability of this system was tested for forecasts of Typhoon Nari in 2007 and a low-pressure event on August 27, 2009. This system responded correctly to the given typhoon information for Typhoon Nari. In particular, for the low-pressure event the system warned of storm surge occurrence approximately 68 hours ahead.

• 한국해양공학회지
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• 제20권3호
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• pp.37-44
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• 2006

Each year, the coast of Busan is badly damaged, due to storm surge. The damages are greatly dependent upon the local peculiarities of the region in which the storm surge occurs. So, in order to prevent/reduce recurrence of the disaster due to the storm surge, it is very important to investigate the fluctuation characteristics of the storm surge height, related to the local peculiarities at each coastal area in which the occurrence of the disaster is expected. In this paper, using the numerical model, the storm surge was simulated to examine its fluctuation characteristics at the coast of Busan Typhoons of Sarah (5914), Thelma (8705) and Maemi (0314), which caused terrible damage to the coastal areas alongthe coast of Busan in the past, were taken as an object of the storm surge simulations. Moreover, the storm surge due to virtual typhoons, which were combined with the characteristics of each proposed typhoon (Maemi, Sarah, Thelma), compared to the travel routes of other typhoons, was predicted. As expected, the results revealed that the storm surge heights are enhanced at the coastal region with the concavity like a long-shaped bay. Also, the storm surge heights, due to each typhoon, were compared and discussed at major points along the coast of Busan, related to the local peculiarities, as well as the characteristics and the travel route of the typhoon.

• 한국해양공학회지
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• 제20권3호
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• pp.45-53
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• 2006

Each year, the south coast of Korea is badly damaged from storm surge. The damages are greatly dependent upon the local peculiarities of the region where the storm surge occurs. So, in order to prevent/reduce recurrence of the disaster, it is very important to investigate the fluctuation characteristics of the storm surge height, related to the local peculiarities at each coastal area where occurrence of the disaster is expected. In this paper, using the numerical model, the storm surge was simulated to examine its fluctuation characteristics at the Gyeongnam coast (southeast coast of Korea). Typhoons of Sarah (5914), Thelma (8705) and Maemi (0314), which caused terrible damage to the coastal area in the southeast coast of Korea in the past, were used forstorm surge simulations. Moreover, the storm surge due to virtual typhoons, which were combined the characteristics of each proposed typhoons (Maemi, Sarah, Thelma)with the travel route of other typhoon, was predicted. As expected, the results revealed that the storm surge heights are enhanced at the coastal regions with the concavity like a long-shaped bay. Also, the storm surge heights, due to each typhoon, were compared and discussed at major points along the Gyeongnam coast, related to the local peculiarities, as well as the characteristics and the travel route of typhoon.

• 한국해안·해양공학회논문집
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• 제28권5호
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• pp.284-291
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• 2016

빈도별 최대풍속을 발생시키는 태풍조건을 역추적함으로써 빈도별 표준태풍을 생성할 수 있다(Kang et al., 2016). 본 연구에서는 이렇게 얻어진 표준태풍의 해일모의를 통해 서해안 영광지역의 해일고 빈도해석을 수행하는 방안을 제시하고자 한다. 본 연구에 사용된 모형은 MIKE21모형으로서 태풍 BOLAVEN(1215)에 대한 검증 결과 서해안 여러 지역에서 관측결과와 비교적 잘 일치하는 결과를 얻었다. 서해안 태풍해일특성을 감안하여 경로변경을 설정한 후 빈도별 해일고를 구한 결과는 관측치로부터 산정된 결과와 부합하는 결과를 보이고 있다. 이 방법은 관측자료가 충분치 않은 곳에서 수많은 태풍에 의한 해일모의를 수행하는 기존 방법에 비해 빈도별로 한 개의 태풍만을 대상으로 하므로 매우 효율적인 방법이다.

• 한국해안·해양공학회논문집
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• 제20권1호
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• pp.93-100
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• 2008

Multi-nesting grid system을 이용한 한국해양연구원의 해일모델을 해일고 산출에 사용하기 위해 검증하였다. 다양한 수치실험은 2003년 9월 내습한 태풍 매미를 기준으로 이루어졌다. 이 태풍해일모델의 성능을 알아보기 위해 조석검증을 비롯하여 개방경계조건, 격자 크기 그리고 태풍의 진로 등에 대한 일련의 수치실험이 실시되었다. 본 연구에서 기상입격자료인 해면기압장과 바람장은 CE wind 모델로 계산하였다. 총 11개 조위관측소의 1분 간격 조위자료와 모델 결과를 비교하였으며, 해일고를 성공적으로 재현하였다. 이러한 실험들은 정밀한 해일고 산출에 있어 기상자료의 중요성과 상세정밀격자의 필요성을 강조하기 위한 것이다. 이 태풍해일 모델은 보다 세밀한 검증과정을 거친다면 해일고 예측을 위해 상시 운용될 수 있다고 사료된다.

• 한국해안·해양공학회논문집
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• 제21권1호
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• pp.1-14
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• 2009

태풍의 주요 매개변수 변화에 따른 영향을 판단하는데 용이하도록 직선화된 가상태풍을 생성시켰다. 이러한 가상태풍 모의를 통해 경남해역을 대상으로 해일양상 변화를 고찰하였다. 이를 위해 태풍 MAEMI(0314)를 직선화한 가상태풍의 적절성을 검토한 후, 총 175개 CASE의 가상태풍모의를 수행하였다. 모의결과, 마산과 통영 해역은 지형적인 영향으로 다른 해역에 비해 상대적으로 높은 해일고가 발생되는 것으로 나타났다. 특히 마산해역의 경우 MAEMI와 동일한 강도의 태풍 내습시 경로에 따라 최대 2.50 m의 해일고가 발생 가능한 것으로 모의되었다. 마산 이외의 해역에서는 태풍 MAEMI의 해일고가 최대치에 근접하는 결과를 보여 MAEMI의 경로가 최악의 피해를 주는 경로였던 것으로 판단된다. 기압에 의한 수위 상승효과는 바람에 비해 상대적으로 크게 작용하며, 태풍의 중심에서 그 효과는 최대가 되는 것으로 나타났다.

• 한국해안·해양공학회논문집
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• 제27권1호
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• pp.25-37
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• 2015

태풍발생시기의 조석-해일 비선형 특성을 분석하였다. Chi-square test를 통한 정량적 해석결과 목포를 비롯한 서남해안 지역에서 비선형성이 가장 우세하였고 서해안과 남동해안에서는 뚜렷하게 나타나지는 않고 있다. 태풍-해일 발생패턴을 첨두형과 지속형으로 구분하여 해석하였는데 조석-해일 비선형성은 지속형에서 다소 높게 나타나는 것으로 확인되고 있다. 서해안의 경우 저조시 해일발생빈도가 높지 않게 나타나는 이유는 남해안경로 태풍에 의한 음해일 발생이 많은 것과 무관치 않은 것으로 보인다. 그러나 서해안경로 태풍에 대해서는 태풍통과 이후 저조시에 최대해일고가 발생하는 조석-해일 비선형효과가 두드러지게 나타나고 있다. 남동해안의 경우에는 첨두형 태풍이 잦아 비선형효과에 의한 저조시 해일발생빈도가 낮은 것으로 분석되고 있다. 이에 따라 남해안경로 태풍의 경우 통과인근지역에서는 고조시에도 대규모 해일발생이 가능하므로 태풍-해일에 의한 범람 위험도가 매우 높은 것으로 판단된다.